/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2020 Photon Storm Ltd.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

 var Class = require('../../utils/Class');
 var CONST = require('../const');
 var File = require('../File');
 var FileTypesManager = require('../FileTypesManager');
 var GetFastValue = require('../../utils/object/GetFastValue');
 var IsPlainObject = require('../../utils/object/IsPlainObject');
 var GetURL = require('../GetURL');
 
 /**
  * @classdesc
  * A single Image File suitable for loading by the Loader.
  *
  * These are created when you use the Phaser.Loader.LoaderPlugin#image method and are not typically created directly.
  *
  * For documentation about what all the arguments and configuration options mean please see Phaser.Loader.LoaderPlugin#image.
  *
  * @class ImageFile
  * @extends Phaser.Loader.File
  * @memberof Phaser.Loader.FileTypes
  * @constructor
  * @since 3.0.0
  *
  * @param {Phaser.Loader.LoaderPlugin} loader - A reference to the Loader that is responsible for this file.
  * @param {(string|Phaser.Types.Loader.FileTypes.ImageFileConfig)} key - The key to use for this file, or a file configuration object.
  * @param {string|string[]} [url] - The absolute or relative URL to load this file from. If undefined or `null` it will be set to `<key>.png`, i.e. if `key` was "alien" then the URL will be "alien.png".
  * @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - Extra XHR Settings specifically for this file.
  * @param {Phaser.Types.Loader.FileTypes.ImageFrameConfig} [frameConfig] - The frame configuration object. Only provided for, and used by, Sprite Sheets.
  */
 var ImageFile = new Class({
 
     Extends: File,
 
     initialize:
 
     function ImageFile (loader, key, url, xhrSettings, frameConfig)
     {
         var extension = 'png';
         var normalMapURL;
 
         if (IsPlainObject(key))
         {
             var config = key;
 
             key = GetFastValue(config, 'key');
             url = GetFastValue(config, 'url');
             normalMapURL = GetFastValue(config, 'normalMap');
             xhrSettings = GetFastValue(config, 'xhrSettings');
             extension = GetFastValue(config, 'extension', extension);
             frameConfig = GetFastValue(config, 'frameConfig');
         }
 
         if (Array.isArray(url))
         {
             normalMapURL = url[1];
             url = url[0];
         }
 
         var fileConfig = {
             type: 'image',
             cache: loader.textureManager,
             extension: extension,
             responseType: 'blob',
             key: key,
             url: url,
             xhrSettings: xhrSettings,
             config: frameConfig
         };
 
         File.call(this, loader, fileConfig);
 
         //  Do we have a normal map to load as well?
         if (normalMapURL)
         {
             var normalMap = new ImageFile(loader, this.key, normalMapURL, xhrSettings, frameConfig);
 
             normalMap.type = 'normalMap';
 
             this.setLink(normalMap);
 
             loader.addFile(normalMap);
         }
 
         this.useImageElementLoad = loader.imageLoadType === 'HTMLImageElement';
 
         if (this.useImageElementLoad)
         {
             this.load = this.loadImage;
             this.onProcess = this.onProcessImage;
         }
     },
 
     /**
      * Called automatically by Loader.nextFile.
      * This method controls what extra work this File does with its loaded data.
      *
      * @method Phaser.Loader.FileTypes.ImageFile#onProcess
      * @since 3.7.0
      */
     onProcess: function ()
     {
         this.state = CONST.FILE_PROCESSING;
 
         this.data = new Image();
 
         this.data.crossOrigin = this.crossOrigin;
 
         var _this = this;
 
         this.data.onload = function ()
         {
             File.revokeObjectURL(_this.data);
 
             _this.onProcessComplete();
         };
 
         this.data.onerror = function ()
         {
             File.revokeObjectURL(_this.data);
 
             _this.onProcessError();
         };
 
         File.createObjectURL(this.data, this.xhrLoader.response, 'image/png');
     },
 
     /**
      * Handles image load processing.
      *
      * @method Phaser.Loader.FileTypes.ImageFile#onProcessImage
      * @private
      * @since 3.60.0
      */
     onProcessImage: function ()
     {
         var result = this.state;
 
         this.state = CONST.FILE_PROCESSING;
 
         if (result === CONST.FILE_LOADED)
         {
             this.onProcessComplete();
         }
         else
         {
             this.onProcessError();
         }
     },
 
     /**
      * Loads the image using either XHR or an Image tag.
      *
      * @method Phaser.Loader.FileTypes.ImageFile#loadImage
      * @private
      * @since 3.60.0
      */
     loadImage: function ()
     {
         this.state = CONST.FILE_LOADING;
 
         this.src = GetURL(this, this.loader.baseURL);
 
         if (this.src.indexOf('data:') === 0)
         {
             console.warn('Local data URIs are not supported: ' + this.key);
         }
         else
         {
             this.data = new Image();
 
             this.data.crossOrigin = this.crossOrigin;
 
             var _this = this;
 
             this.data.onload = function ()
             {
                 _this.state = CONST.FILE_LOADED;
 
                 _this.loader.nextFile(_this, true);
             };
 
             this.data.onerror = function ()
             {
                 _this.loader.nextFile(_this, false);
             };
 
             this.data.src = this.src;
         }
     },
 
     /**
      * Adds this file to its target cache upon successful loading and processing.
      *
      * @method Phaser.Loader.FileTypes.ImageFile#addToCache
      * @since 3.7.0
      */
     addToCache: function ()
     {
         var linkFile = this.linkFile;
 
         if (linkFile && linkFile.state === CONST.FILE_COMPLETE)
         {
             if (this.type === 'image')
             {
                 this.cache.addImage(this.key, this.data, linkFile.data);
             }
             else
             {
                 this.cache.addImage(linkFile.key, linkFile.data, this.data);
             }
         }
         else if (!linkFile)
         {
             this.cache.addImage(this.key, this.data);
         }
     }
 
 });
 
 /**
  * Adds an Image, or array of Images, to the current load queue.
  *
  * You can call this method from within your Scene's `preload`, along with any other files you wish to load:
  *
  * ```javascript
  * function preload ()
  * {
  *     this.load.image('logo', 'images/phaserLogo.png');
  * }
  * ```
  *
  * The file is **not** loaded right away. It is added to a queue ready to be loaded either when the loader starts,
  * or if it's already running, when the next free load slot becomes available. This happens automatically if you
  * are calling this from within the Scene's `preload` method, or a related callback. Because the file is queued
  * it means you cannot use the file immediately after calling this method, but must wait for the file to complete.
  * The typical flow for a Phaser Scene is that you load assets in the Scene's `preload` method and then when the
  * Scene's `create` method is called you are guaranteed that all of those assets are ready for use and have been
  * loaded.
  *
  * Phaser can load all common image types: png, jpg, gif and any other format the browser can natively handle.
  * If you try to load an animated gif only the first frame will be rendered. Browsers do not natively support playback
  * of animated gifs to Canvas elements.
  *
  * The key must be a unique String. It is used to add the file to the global Texture Manager upon a successful load.
  * The key should be unique both in terms of files being loaded and files already present in the Texture Manager.
  * Loading a file using a key that is already taken will result in a warning. If you wish to replace an existing file
  * then remove it from the Texture Manager first, before loading a new one.
  *
  * Instead of passing arguments you can pass a configuration object, such as:
  *
  * ```javascript
  * this.load.image({
  *     key: 'logo',
  *     url: 'images/AtariLogo.png'
  * });
  * ```
  *
  * See the documentation for `Phaser.Types.Loader.FileTypes.ImageFileConfig` for more details.
  *
  * Once the file has finished loading you can use it as a texture for a Game Object by referencing its key:
  *
  * ```javascript
  * this.load.image('logo', 'images/AtariLogo.png');
  * // and later in your game ...
  * this.add.image(x, y, 'logo');
  * ```
  *
  * If you have specified a prefix in the loader, via `Loader.setPrefix` then this value will be prepended to this files
  * key. For example, if the prefix was `MENU.` and the key was `Background` the final key will be `MENU.Background` and
  * this is what you would use to retrieve the image from the Texture Manager.
  *
  * The URL can be relative or absolute. If the URL is relative the `Loader.baseURL` and `Loader.path` values will be prepended to it.
  *
  * If the URL isn't specified the Loader will take the key and create a filename from that. For example if the key is "alien"
  * and no URL is given then the Loader will set the URL to be "alien.png". It will always add `.png` as the extension, although
  * this can be overridden if using an object instead of method arguments. If you do not desire this action then provide a URL.
  *
  * Phaser also supports the automatic loading of associated normal maps. If you have a normal map to go with this image,
  * then you can specify it by providing an array as the `url` where the second element is the normal map:
  *
  * ```javascript
  * this.load.image('logo', [ 'images/AtariLogo.png', 'images/AtariLogo-n.png' ]);
  * ```
  *
  * Or, if you are using a config object use the `normalMap` property:
  *
  * ```javascript
  * this.load.image({
  *     key: 'logo',
  *     url: 'images/AtariLogo.png',
  *     normalMap: 'images/AtariLogo-n.png'
  * });
  * ```
  *
  * The normal map file is subject to the same conditions as the image file with regard to the path, baseURL, CORs and XHR Settings.
  * Normal maps are a WebGL only feature.
  *
  * In Phaser 3.60 a new property was added that allows you to control how images are loaded. By default, images are loaded via XHR as Blobs.
  * However, you can set `loader.imageLoadType: "HTMLImageElement"` in the Game Configuration and instead, the Loader will load all images
  * via the Image tag instead.
  *
  * Note: The ability to load this type of file will only be available if the Image File type has been built into Phaser.
  * It is available in the default build but can be excluded from custom builds.
  *
  * @method Phaser.Loader.LoaderPlugin#image
  * @fires Phaser.Loader.LoaderPlugin#ADD
  * @since 3.0.0
  * @param {(string|Phaser.Types.Loader.FileTypes.ImageFileConfig|Phaser.Types.Loader.FileTypes.ImageFileConfig[])} key - The key to use for this file, or a file configuration object, or array of them.
  * @param {string|string[]} [url] - The absolute or relative URL to load this file from. If undefined or `null` it will be set to `<key>.png`, i.e. if `key` was "alien" then the URL will be "alien.png".
  * @param {boolean} [isStatic=false] - 是否是静态资源 
  * @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - An XHR Settings configuration object. Used in replacement of the Loaders default XHR Settings.
  *
  * @return {this} The Loader instance.
  */
 FileTypesManager.register('image', function (key, url, isStatic, xhrSettings)
 {
     if (Array.isArray(key))
     {
         for (var i = 0; i < key.length; i++)
         {
             //  If it's an array it has to be an array of Objects, so we get everything out of the 'key' object
             this.addFile(new ImageFile(this, key[i]));
         }
     }
     else
     {
         this.addFile(new ImageFile(this, key, url, xhrSettings));
     }
 
     return this;
 });
 
 module.exports = ImageFile;
 